1.Stand up.
![](http://static.xuejinqu.com/qimg/f0e/f0e8e6270fa86e52750812c5b203becd.png)
2.Point to the desk.
![](http://static.xuejinqu.com/qimg/c5f/c5fbbdf7eef63d2fc43f7f996e2d3271.png)
3.Point to the chair.
![](http://static.xuejinqu.com/qimg/966/9663647c2deff9e31beef1bf552c6975.png)
4.Point to the blackboard.
![](http://static.xuejinqu.com/qimg/e97/e97e742c9296a6f822fd24a360f99fa1.png)
5.Hi, Mr Li.
![](http://static.xuejinqu.com/qimg/2e9/2e9d329ae6a715edfd43e3c55cb05bcf.png)
![](http://static.xuejinqu.com/images/y-prise.png)
同类型试题
![](http://static.xuejinqu.com/images/medal.png)
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
![](http://static.xuejinqu.com/images/avatar.png)
![](http://static.xuejinqu.com/images/avatar.png)
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
![](http://static.xuejinqu.com/images/avatar.png)
![](http://static.xuejinqu.com/images/avatar.png)